Tool retainer



Feb. 8 193 8.

J. H. PARSONS ET AL TOOL RETAINER Original Filed Oct. 31, 1932 3Sheets-Sheet 2 INVENTOR;

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' TOOL RETAINER I Original Filed Oct. 31, 1932 3 Sheets-Sheet 3 INVENTOR$707211 27G Pafsons Patented Feb. 8, 1938 PATENT OFFICE TQOL RETAINERJohn 1]. Parsons, Bloomfield Hills, and Lawrence 8. Lamb, Groase PointePark, Mich.

muting. owner a1, 1932, Serial No.

Renewed July 9, 1937 12 Claims.

This invention relates to tool-retaining devices, such as are commonlyused to retain punches, dies, drills and the like in their holders. Itis usually desired that'tools of this class be interchangeable in theirholders, and various means have in the past been employed to removablysecure them. Such previously used retalning means have beenunsatisfactory for a number of reasons. Those so designed as to retainthe tools with adequate firmness necessitated the expenditure of toomuch time and trouble in attaching and removing the tools. while many ofthose designed to permit rapid interchanging of the retained tools havenot provided adequate security. Some such retainers designed for quickaction provide adequate security for circular punches, for example, butnot.

such-shanks frequently dare not employ them;

as in order to do so safely they would have to carry on hand aprohibitively expensive reserve supply, or special cutting or grindingequipment, to prevent the danger of a tool breakage stopping production.

The primary object of the present invention is to provide a toolretainer subject to none of the foregoing briefly summarizedshortcomings and defects, and which, while permitting instantaneousremoval and insertion of a tool in the retainer, retains the tool withsuch firmness as to prevent any possibility of either rotative orendwise movement of the tool with respect to the retainer.

Another object of this invention is the production of such a retainerwhich is of simple and inexpensive construction. and which is utilizablein conjunction with tools and holders of conventional designs now'inuse, merely necessitating slight alterations thereof, to effect whichalterations special machinery is not required. I

A further important object is the provision of such retaining meansinstallable in less space than those heretofore used, and without regardto the relative hardnesses of the metal in which the tool shank and theretainer itself are installed.

Another object is the provision of an improved tool retainer so designedthat the retainer block need not be specially hardened.

Another important object is the incorporation in such a retainerconstruction of indicating means enabling easy determination by theoperation as to whether ornot the tool is properly locked in theretainer. 7

A still further object is the provision of improved pilot means insuringinsertion of the tool in the retainer in the proper manner.

Another object is the provision of an improved retainer blockconstruction enabling mounting interchangeably retained tools on closercenters. I

Another object. is the provision of means for interchangeably mounting aseries of tools in an elongated retainer without the necessity ofregrinding each tool socket or other aperture after a hardeningoperation to correct inaccuracies so introduced, but in which anunhardened re- 7 tainer is used with inserted sockets or the likeindividually hardened, together with improved means for sup rting toolsof unusual length.

Other obiec's and advantages will be apparent from the followingdescription whereinreference is made to the accompanying drawingsillustrating preferred embodiments of our invention, and wherein similarreference numerals designate similar parts throughout the several views.y

In the drawings:

Figure 1 is a vertical sectional view taken sub-' stantiallylongitudinally through a punch retainer incorporating the principles ofour invention, showing a punch secured therein, and also fragmentarilyshowing a punch holder, stripper plate, a piece of sheet stock beingworked upon, and a die;

Figure 2 is a top plan view of the punch retainer removed from thebacking plate and punch holder, taken substantially on the line 2-4 ofFigure l and looking in the direction of the arrows;

Figure 3 is a fragmentary top plan view with the backing plate in place,taken as if on line 3-3 of Figure 1;

Figure 4 is a fragmentary top plan view of the punch and detent;

Figure 5 is a fragmentary detail section similar to Figure 1 in theparts shown, but i11ustrating the punch released, or before beingsecured;

Figure 6 isa similarly taken fragmentary sectiontof a somewhat modifiedpunch retainer inpiloting device carried by the stripper plate;

Figure 8 is a top plan view of a plurality or retainers of this formarranged in series, show= ing the holder in one instance prepared forthe retainer and tool which are not yet installed;

Figures 9 and 10 are top and side views respec- 'tively of the toolsocket bushing;

' its insertion in the retainer.

, Figure 11 is a top plan Vi8W,'&1SO with the backing plate removed, ofanother series-mounting arrangement for punches, four of which are showninstalled;

Figure 12 is a top plan view of a plurality of our improved retainerblocks of different sizes arranged in interfitting relation; and

Figure 13 is a similar-view showing another arrangement.

Referring now to the drawings: Reference character represents the mainblock or body of a punch retainer, utilized as illustrative of a typicalapplication of our invention. A cylindrical bcre 2| is formed thereinadapted to receive a punch shank, as the shank 22 of the punch.23. Atransverse groove is formed in and adjacent the upper end of the shanldof the punch, as indicated at 24, Figures 1 and 5. The preferred form ofthis groove is clearly shown in the drawings, from which it will beobserved that a generally plane anguiarly arranged surface 24' forms itsupper wall. The top edge of the punch may also be chamiered, as at 25,to: facilitate A depression is formed in the top of the retainer block20 adjacent the upper extremity of the tool shank socket 2|. Thisdepression may take the form of a simple miiied slot 26 disposedtransversely of the hiock, as shown in Figures 1 and 2." Terminating inthe slot 26 and vertically arranged beside the punch socket 2| is a bore21 havinga' reduced upper portion". Vertically reciprocable in theaperture 2'|28 is a stem 29,

carrying a cupped collar and spring abutment,

. aperture and bears at its other end-against member 30 to urge the pindownwardly. Secured to the upper extremity of the pin and arrangedtransversely thereof is the wedglngcam member 32, which is housed withinthe depression formed by the slot 26, and of course also serves as astop to limit downward movement of the pin 29. Also within thedepression formed by the slot 2G, slidably fitting between the bacfingplate and the bottom of the slot and arranged between the wedging member32 and the punch socket 2|, is

i the locking detent 33, the central portion of the wedge 32 as thelatter is forceddownwardly under the influence of the spring 3|. Inorder to position the detent 33 and prevent its sliding from the recess26, it may be formed with rearwardly projecting ends 34 engagingthe'sides of the wedge 32, as shown in Figures 2 and 3. The

locking surface 35 of the detent may be partly cylindrical, so that itcontacts the locking surface 24' or the punch shank groove along astraight line, and the lower surface of the detent which 1 overhangs thesocket may be angularly cut ,out, as at 36, to form a cam surfaceengageable by the chamfered upper end of the punch shank by which thedetent may be forced clear of the socket as the punch is inserted whenthe wedge is released.

The angle between the wedge member 32 and the rear face of the detent 33is such that the wedge cannot be forced upwardly by pressure inthedirection of the arrow 31 exerted through the detent. While-as abovepointed out, the surface 32' of the wedge 32 and the rear surface 33 ofthe detent 33 are arranged at a wedging angle, so that'the wedge cannotbe urged upwardly by lateral pressure exerted through the detent, theinclined engaging surface 24" of the punch shank aperture is notarrangedat a locking angle relatively to the portion of the lockingsurface 35 of the detent it engages, so that when the detent is releasedby upward movement of the wedge memher, a retained tool may be removedfrom the socket by merely pulling the same downwardly, the detent'memberbeing thereby forced laterally in the direction of arrow 3! and out ofthe tool socket. The wedge is moved upwardly by pushing upwardly uponthe plunger 30, either manually,

or if it is inaccessible, by 'means of a suitable tool (not shown). Theplunger, of course, may or may not project from its aperture 21,depending upon the clearance available in the particular toolinstallation. If the plunger cannot project, any pointed or suitablysized member may be inserted in the aperture to enable forcing theplunger inwardly. In order to permit insertion of the punch the detentis first released, so that it is free to move laterally, by pushing thewedge 32 and associated parts upwardly, after which the shank of thepunch may be inserted in the socket, the chamfered surfaces 36cooperating to force the detent out of the socket, permitting fullinsertion of the tool, after which release of the upward pressureagainst the plunger permits the wedge 32 to move downwardly, forcing thedetent 33 back into the punch socket, and into engagement with the slot24 in the punch shank. The tool is thereupon locked against removal,since no amount of force in the direction 31 gen erated by downward pullupon the tool is suilicient to force the'wedge 32 upwardly. It will benoted that the engagement of the locking surface of the detent with theinclined surface 24 of the punch shank slot tends to force the punchupwardly within its socket, and thus'maintains the top of the punch inengagement with the top of the socket, preventing longitudinalreciprocation. or slopping of the punch shank in the socket, whichmight, upon subjection of the tool to hard and rapid usage, result inpeening of the upper end of the punch shank, or crystallization of themetal subjected to the percussion thus generated. The top of the punchsocket and retainer recess 26 may if desired be closed by a backingplate, as 39, secured to the top of the plate 20 in any suitablefashion, as. by the same screws 40 which-secure the retainer block tothe punch holder 4|. In the backing plate is formed preferably of reamerdrill size, and the block.

a clearance slot or aperture 42 wherein the wedge member \32 ispermitted to move upwardly, as

shown in\ Figure '5.

Preferably the shank of the tool is flattened as at 43 immediately abovethe locking slot, and the detent'is movable rearwardiy only far enoughto permit full insertion of the tool when this flat 43 is aligned withthe detent, which thus also serves as a pilot preventing improperinsertion of the tool with the locking groove disaligned with thedetent.

Although only parts of the illustrative punch press appear in thedrawings, it will be seen that in Figure 1 a "button die is shownarranged for cooperative reception of the punch. The die, whether ofthis or any other removable type, may of course also be positioned byone of our improved retainers, although a showing thereof is notincluded, inasmuch as it would serve merely to unnecessarily elaboratethe drawings.

It will be seen that close size Ilmits need not be observed in formingthe locki lfl P rts or the apertures in which they move, and that thedetent 33, wedge 32 and rod 2! may be formed of bar stock which isrolled in manufacture to the desired cross section, and then out oil tothe desired lengths.- The retainer block 20 may be of low carbon steel,which is copper-plated before final reaming of the punch socket 2i anddetent slot 26, after which it may be case-hardened upon only thesesurfaces from which the copper-plating has been removed. The apertures44 are being unhardened, it may in assembly upon the tool be positionedupon the punch holder, the holes drilled in the latter by means of afull sized drill, using theblock as a template, and both apertures thenreamed at once, thus making disalignment virtually impossible.

By reason of the lateral engagement of the rearward extensions 34 of thedetent with the sides of the wedge member, the detent is positivelypositioned against lateral displacement without the necessity ofemploying any other guides except the backing plate and the bottom ofthe slot 26. Thus the slot may be opened at its ends, and thus also aplurality of detents and wedge members may be arranged in a singleelongated slot when a series of punches is employed. Note in thisconnection the typical series arrangement shown in. Figure 8, in whichthe single elongated slot 26=is designed to accommodate a piuralityofdetents 33 and interfitting wedge members 32 the former of which engagea. plurality of punches as 23 having their sides carrying the retaininggrooves exposed to the slot. The series arrangement shown in this viewwill presently be described in greater detail.

In Figure 6 is shown an illustrative embodlment typifying the ease withwhich our improved retainer is installable in tool assemblies nowconsidered impossible of adaptation to interchangeable retainers. Inthis construction, which will be recognized as typical, aforming orshearing blade 45 is carried by the press adjacent the punch 23", thepunch retainer block 20' being thereby necessarily limited in size; If,as in the construction shown, one of the seeming screws as 4!! liesimmediately behind the punch, it becomes a difficult matter to installan interchangeable retainer of any of the types now known, as if anattempt is made to put ordinary retainers in the body of the blademember 45 in the manner in which our improved retainer is showninstalled, the differences of hardness of the metals, of the shearingblade and the retainer block, through the thin wall of which between theblade and punch shank the detent must project, make it impossible tohold the aperture through which the detent works to close limits, or tohold the two sections of the aperture in exact alignment. If then thedesign of the interchangeable retainer .is such as is commonly the case,that the detent and its aperture must fit to close limits, such aninstallation islmpossible. With our improved construction on the otherhand, the detent works through what may be termed a clearance: slotonly. The size limits of these parts are relatively unimportant and neednot be close. The locking means may be installed in the body of theblade in the manner shown in Figure 6, with the detent member 33projecting through an aperture (undesignated) in the front of the block20. The plunger 30 by means of which the punch is released is then alsoeasily accessible from the front of the tool, making this a desirablemethod of installation even though there might be room for the retainerin the block 20 behind the punch. Analogous parts to those shown anddescribed in connection with the first embodiment will be seen to havebeen. given like reference numerals with the addition of primeexponents. Their similar funotioningwill be easily understood, anddetailed repetition of the description of these parts will accordinglybe omitted as unnecessary.

Figure '7 shows another somewhat modified form particularly adapted foruse in connection with long punches which project farther from theholder than is usual. Such a punch is shown at 23 In this embodiment'the punch socket is formed of an individually hardened and groundbushing 2| which may be press fitted in the unhardened retainer block 20and provided with a flange as 43 at itsupper end which serves toadditionally position it when clamped beneath the backing plate 39 uponassembly of the retainer upon the punch holder in the manner shown. Thesocket bushing 2| projects down wardly from the retainer block to form asupport for the elongated punch shank, as clearly shown in the drawings.The top of .the socket bushing is cut away as. at 4'! (Figures 9 and 10)to permit the detent member 33 to enter the locking groove 24 in thetool shank. If a stripper plate as 48 which is rigidly fixedto the bedor table of the machine is employed, it may carry a pilot bushing as 49adapted to serve as a guide for the socket bushing 2 i to properly alignthe punch with the die 50, and thus prevent damage to either in event ofany sloppiness in the punch holder-a common condition. The remaininganalogous parts have been given like reference numerals with cubeexponents.

As shown in Figure 8, the socket bushings 2i form a convenient meanswhereby a. number of punches. may be arranged in an elongated series ina retainer bar as 20 which may be of unhardened metal. At the presenttime great difficulty isencountered in arranging a long series ofpunches in a single bar carrying interchangeable retainers forcooperation with a similarly arranged series of dies which are usuallyalso mounted in an elongated bar, as after drilling the socket holes thebars must be hardened, .70

bar may be left unhardened and the holes for the socket bushings 2|drilled upon proper centers, the bushings which are of course previouslyhardened and ground, (a simple production operation upon such pieces)are then press fitted into the bar, which is then completed insofar asthe arrangement of the punch sockets therein is concerned. The die baris oi course similarly formed, and it will be understood that the sameretaining means is preferably employed in conjunction with the dies (andthat it is equally adaptable to other tools as well). The detent membersas 33 and wedges as 32 may be housed in a single elongated slot 28traversing the bar.

As indicated in Figure 11, more than one tool as 23 may be held by asingle detent, as 33 tainer blocks and backing plates is best broughtout in plan 'view Figures 12 and 13, showing typical nestings of punchretainers of various sizes, and bringing out the manner in which theirshaping permits arrangement of a plurality of punches on close centersthough mounted instandardized retainers; As shown in Figure 12 the noseof each retainer block as 20 is rounded concentrically about the axis ofthepunch socket 35 H and is filleted or flared outwardly as at 53 tomeet the side walls of the retainer only at a point well back of thenose of the block and punch axis. This back radius of the flare .ispreferably greater than the nose radius of the largest block, whichassists the interfitting of the retainers, as shown, with a minimumspacing less than is ordinarily obtainable.

While it will be apparent that the illustrated embodiments of ourinvention herein disclosed are well calcuiated to adequately fulfill theobjects and advantages herein stated, it is to be understood that theinvention is susceptible to ,variation, modification and changewithinfthe spirit and scope of the subjoined claims.

What we claim is:

1. In a tool retainer, a block member having a tool socket therein and adepression in its rear surface adjacent and intersecting the socket,

a backing plate arranged over the depression, a

detent member slidable in the depression between and confined by thebottom of the latter and the backing plate which thus cooperate to forma slideway, said detent member having an inclined rear surface, anactuating member for.

' in adapted to receive the tool shank, a detent t me is projected towardly of the socket.

thereofabutting the detent, and being adapted when the tool is so fullyinserted and the detent engage in the slot in the tool shank.

3. In a metal forming device, a holdena bladelike forming member carriedthereby, a tool retainer block carried by the holder adjacent the bladeand having a tool sockettherein, a channel formed of registeringopenings in the blade member and retainer block, and tool locking meanscarried by the blade member and including a .detent in the channelmovableinwardly and out- 4. In combination with a tool having atransversely slotted shank, a tool retainer comprising a member socketedto receive the tool shank, a detent member projectable into, the socketto engage the slot in the tool shank and movable therefrom to releasethe same, a wedging member arranged substantially behind the detentmember for looking the detent member in projected position, and meansfor moving the'wedge member to lock or release the detent at will, theslotted area of the tool shank engaged'by the detent being disposed at alarge angle relatively to the tool socket, whereby the detent urges thetoolfarther inthe socket as the detent is forced toward the shank.

5.- In combination with a tool retainer having a socket therein, a toolhaving a shank insertable in the socket, the shank being provided with atransverse depression having an inclined face arranged at a large anglerelatively to the shank, a detent member having a portion curved aboutan axis transverse to that of the socket and projectable into the socketfor cooperative engagement with the inclined face of the depression inthe shank, whereby the detent engages the tool shank along a transverseline, and upon being urged thereagainst urges. the tool shank inwardlyof the socket.

6. In a tool retainer, a block member having a tool socket therein and adepression in its rear surface adjacent and intersecting the socket, abacking plate arranged over the depression and having an aperturetherein also overlying part of the depression, a detent'member in thedepression confined by the bottom thereof and by the backing plate andslidable therebetween and inwardly and outwardly of the tool socket, andan actuating member for the detent movable transversely of the grooveand backing plate and in the aperture in the latter.

7. In combination with a tool having a shank, a depression in the sideof the shank, and a longitudinally' arranged guiding portion carried bythe shank and extending from the depression :to its end, a retainercomprising a block having a tool socket therein, a detent carried by theblock and movable inwardly and outwardly of the socket but having aportion adapted to project partially into thev tool socket when thedetent is fully retracted and engageable with the guiding portion of thetool shank while the tool is being inserted to prevent insertion of thetool except with such surfaces in desired relation.

8. In a metal forming device, a holder, 9. bladelike forming membercarried thereby, a punch, and means for removably supporting the punchin the holder, comprising a retainer carried by the holder having asocket therein for the punch and arranged adjacent the blade, the blademember and retainer having aligned apertures therein forming a channelintersecting the socket, and punch locking means including a detentmovable in said channel in and outwardly of the socket and operable fromthe opposite side of the forming member to that occupied by the socket.

9. In combination with a tool having a shank and a transverse slot inthe shank, a tool retainer comprising a, member socketed to receive atool shank, a detent member projectable into the socket to engage anupper surface of the slot in the tool shank, a wedging member formaintaining the detent in projected position, said upper surface of theslot in the tool shank beingarranged at less than a wedging angle withrespect to the direction of projection of the detent member, whereby theengagement of the detent and said surface of the slot in the tool shankurges the tool inwardlyof the socket as the detent is urged toward theshank, and means for releasing the wedge member.

10. Means for removably supporting a plurality of tools, comprising anelongated retainer having a plurality of tool sockets therein andextending substantially therethrough, a channel extending along theopposite surface of the retainer from which the tools are intended toproject and intersecting the sockets, a plurality of detents arranged inthe channel and so movable transversely thereof that one may beprojected laterally into and substantially withdrawn from each socket,an actuating cam member arranged behind each detent, means for movingthe cam members to force the detents into the sockets, and engagingportions carried by the cam members and detents adapted to preventdisplacement of the detent members .along the channel without preventingthe described actuative movement of the detents.

11. In a tool retainer having a socket therein and a channeltransversely intersecting the socket and wider than the maximum width ofthat part of the socket which it intersects, a detent member slidable inthe channel" toward and from the axis of the socket and soiinwardly andoutwardly thereof, said detent extending into said portions of thechannel wider than the intersected part of the socket and beingsupported by said portions when projected into the socket.

12. In a tool retainer having a socket therein, a detent member having aportion curved about an axis transverse to the socket and projectablethereinto, said detent having a supporting base portion projecting ateither end beyond the intersected portion of the socket and within theperipheral line thereof whenyiewed from the side, said detent having asubstantially flat inclined rear surface, and a wedging cam arrangedbehind the detent and having a similarly inclined flat surface inengagement therewith.

JOHN H. PARSONS. mwarmca s. 1m.

